The invention relates to an ascender device for ascending on a double rope composed of a first ascender and a second ascender assembled to one another by securing means, each ascender comprising:                a metal flange in the bottom part of which an aperture is cut out forming a grip on the outside,        a trough arranged at the top part of the flange for passage of the rope,        and a swivel cleat provided with a surface for jamming the rope in the bottom of said trough.        